1988 Crew Cab Build

[joe231]

Originally Posted by JPalmer81

Yeah that was me, took the wife and kids and dog for a little drive along the coast almost all the way to Alyeska, we just kept driving, it drives very nice and smooth. The tires are about shot though so i cant drive it too much till i get some new ones on there.

right on!

[86c20]

if you are going to do a sm465 swap you may also want to do a ranger splitter too. you can overdrive every gear. also if you are going with the 6.2 at some point plz write it up well part numbers and makers as i would like to do some stuff to mine before it goes out and the detriot 453t or cummins commin rail goes in. as you can see i am not rushing for the 6.2 to die lol

[JPalmer81]

Originally Posted by 86c20

if you are going to do a sm465 swap you may also want to do a ranger splitter too. you can overdrive every gear. also if you are going with the 6.2 at some point plz write it up well part numbers and makers as i would like to do some stuff to mine before it goes out and the detriot 453t or cummins commin rail goes in. as you can see i am not rushing for the 6.2 to die lol

I am planning on just using the 6.2L for now, and driving it around these last few days, i think it has plenty of power for a pickup truck. All i plan on doing to it for now is just putting some headers on and making a better cold air injection for it to replace the crap it has on their now. I will take lots of pics when i get going on it. As far as the tranny, i have been looking into the ranger splitter with the 465, I really like that i can split all the gears with it. The price is a little steep, but would probably pay for itself down the road at some point.

[Mattman2010]

First off your truck looks really good. I would like to point out something about the 6.2 diesel motors. They like staying in their RPM range so they are very friendly with an Automatic transmission, when you convert it over to a manual you will realize how much the truck will lug down when you go from (L 1 2 3) 2nd gear to 3rd gear. The th400 will be a way better combo for that truck than the sm465 and it will really be a lot better when towing because you will be able to keep the 6.2 in the RPM range. I know this is your truck and you will do with it as you please, and I respect that, but from my personal experience the manual just doesnt seem worth it.

[JPalmer81]

Originally Posted by Mattman2010

First off your truck looks really good. I would like to point out something about the 6.2 diesel motors. They like staying in their RPM range so they are very friendly with an Automatic transmission, when you convert it over to a manual you will realize how much the truck will lug down when you go from (L 1 2 3) 2nd gear to 3rd gear. The th400 will be a way better combo for that truck than the sm465 and it will really be a lot better when towing because you will be able to keep the 6.2 in the RPM range. I know this is your truck and you will do with it as you please, and I respect that, but from my personal experience the manual just doesnt seem worth it.

I appreciate any and all input, I think you make a good point, and one i have been considering the last few weeks, now that i have gotten to come home for a couple weeks and see how it runs and drives. I think i might not have a choice now though, I think one of the clutch's is going out in it, when i put it in drive it is like the brakes are on, but after you drive it and get it warmed up it is fine, so unless i can find a 4L80E it is gonna be the good ole 465.

[Mattman2010]

Dont get me wrong I would rather have a manual over a automatic any day of the week. The 6.2/Sm465/205 is probably one of the easiest maintained drive trains that you could get in these trucks that will last a long time if well taken care of. For just driving around it will not be that bad. But I think you said you had a camper or trailer that you where going to pull. That is where you are really going to notice the split between 2nd and 3rd on these transmissions. I had a J-Code motor in my truck which is rated at more HP and Tq, and I was pulling our little 20 foot pumper pull stock trailer just to see how the truck did and man just to get out of its way I was putting the foot to the floor. I found out that the combo does better in my k10 (way lighter than one of these crew cabs) and so the crew cab is getting the cummins conversion. If you went with a range splitter that would probably help a lot. That would at least make the 2nd to 3rd shift half as much which would really wake up the truck. Im just trying to point out things I noticed when I did mine. I went with the 6.2 for MPG and it was great for just driving around but once I hooked it to a trailer it sure disappointed me. If you are just pulling your trailer a few times a year I think you will be fine. I went with a cummins not because I tow a lot, but i wasnt that happy with the 6.2 and my dream truck has a cummins in it and I found a deal I couldnt pass up. Either way you go man I cant wait to see it!

Matt

[JPalmer81]

Originally Posted by Mattman2010

Dont get me wrong I would rather have a manual over a automatic any day of the week. The 6.2/Sm465/205 is probably one of the easiest maintained drive trains that you could get in these trucks that will last a long time if well taken care of. For just driving around it will not be that bad. But I think you said you had a camper or trailer that you where going to pull. That is where you are really going to notice the split between 2nd and 3rd on these transmissions. I had a J-Code motor in my truck which is rated at more HP and Tq, and I was pulling our little 20 foot pumper pull stock trailer just to see how the truck did and man just to get out of its way I was putting the foot to the floor. I found out that the combo does better in my k10 (way lighter than one of these crew cabs) and so the crew cab is getting the cummins conversion. If you went with a range splitter that would probably help a lot. That would at least make the 2nd to 3rd shift half as much which would really wake up the truck. Im just trying to point out things I noticed when I did mine. I went with the 6.2 for MPG and it was great for just driving around but once I hooked it to a trailer it sure disappointed me. If you are just pulling your trailer a few times a year I think you will be fine. I went with a cummins not because I tow a lot, but i wasnt that happy with the 6.2 and my dream truck has a cummins in it and I found a deal I couldnt pass up. Either way you go man I cant wait to see it!

Matt

Yeah, I agree about the 6.2/sm465 being a very easy to maintain driveline and that is what attracted me to it. I have had several trucks with the 350/sm465 combo and they were perfect in my eyes, although I have had a 6.0/NV4500 combo that was very nice too. I dont have the camper yet, but it will probably be around 5000lbs and def not more than 10000lbs and I only plan to use it to pull that a couple times a year. I am hoping the upgrades I will be doing to the motor will put it equal to a stock early cummins, so if i can get it to that point I think the 465 will do just fine with it. I appreciate your input, that is what this site is all about, learning from each other. Any other input you have is welcomed. Cant wait to get home and get going on this thing!

[JPalmer81]

I think the wide wheel and fat tire bug has bitten me!!! What are some opinions on some classic white spokes say 12 inches wide with some nice fat thornbirds? I have heard some bad things about the thornbirds, but i have been drooling over them since i was a kid!!! Dont worry i will have a more reasonable set of wheels and tires for long trips, just think that for puttin around town the white spokes and thornys would be sweet and look really good on the crew!

[joe231]

momma always said if you don't have anything nice to say....don't say anything.

[JPalmer81]

Originally Posted by joe231

momma always said if you don't have anything nice to say....don't say anything.

So U dont think it is a good idea, which dont you like, the thornys or the white spokes?

[joe231]

The thornbirds.
They suck offroad (they are a poser tire), but I guess they might be ok on the road just over priced for what they are...
I'd go with some 315/75/16 cooper discoverer STT's if it were me.

But different strokes..
Posted via Mobile Device

[JPalmer81]

Here is a Pic I found on the internet of a nice square with some wide white spokes, kinda what i was thinking of lately.....

[JPalmer81]

Originally Posted by joe231

The thornbirds.
They suck offroad, but I guess they might be ok on the road just over priced.
I'd go with some 315/75/16 cooper discoverer STT's if it were me.

But different strokes..
Posted via Mobile Device

yeah, I have heard that they are not for off road unless you have a lot of power to spin your wheels, but I dont plan on going off road too much, maybe some TSL SX's would be good, I like the Cooopers, i have had 2 sets of those in the past.

[joe231]

Even with a lot of power they dont clean out very well.
They a basically only ok on dry pavement.
I have read that they are bad in the rain.
Posted via Mobile Device

[joe231]

Originally Posted by JPalmer81

Here is a Pic I found on the internet of a nice square with some wide white spokes, kinda what i was thinking of lately.....


Attachment 942070

I like that look!
Posted via Mobile Device

[JPalmer81]

Yeah, I have heard about the rain issue, but supposedly now Interco cuts more sipes into the lugs for better wet traction, I dunno though. The only company that makes the 12" wide white spokes is pro-comp and they are in a 16.5 diameter, so i will be restricted with what tire i can use. All of Interco's tires come in a 16.5 size and BFGoodrich still makes the All terrains in a 33x12.5R16.5, but heard they are on back order nation wide, dont understand why they phased that size out, oh well. I might be changing the front clip to the 73-80 style if I can find one with good metal on it, there is a 76' burb on CL for a pretty good price that has decent metal on it and a 4 speed, so if that is still there in a couple months it might be mine.

[charlie diaz]

I think that I've caught the CC bug and I'm loving the ideas that you have for your truck. I've been looking at every build I can to get ideas for what I want and I just got through reading through yours.

My $.02 about a couple of things:

1. I personally agree with you about the decision to go with the sm465. The truck I had with it was so much fun to drive. It's got the same 3rd gear ratio as the TH400, so it all depends on which rear end gear you have as to how it performs hauling your trailer.

2. I would personally go with some BF Goodrich All Terrains for a good "all-around" tire. It would keep you from having to swap back and forth for your different uses. I've had them on a few different vehicles and they perform really well in almost all of the different driving conditions. (I've never had them in snow though)

But if you want a knobbier tire, I would definitely go with the TSL SX's. I had them on a Jeep I built and they were really great tires for off-roading. They didn't ride too bad on the street either.

Great looking truck by the way!!!

[JPalmer81]

Thanks for the comments Charlie. I have been reading on the CK5 forum that swapping in a sm465 behind these 6.2 makes a big difference, gets rid of the drag from the auto tranny. with the upgrades to the motor, i think it will be a pretty bullet proof set up. Nothing like a sooped up Cummins or anything, which i am not trying to achieve that much power, I would never use all that power for ANYTHING that I will be doing with this truck. Again, my main focus is longevity and good mileage and CHEAP! Plus, without doing some major upgrades on the rest of my driveline, my truck is only designed to handle the power from a stock or mildly upgraded 454, which I think I can achieve, or come close to anyways.

I think I have decided for the big set of tires to go with the 33x12.5R16.5 TSL Bias on the 16.5x12 white spokes and my moderate tire will be the Pro Comp Xtreme All Terrain 285/75R16 on 16x8 white spokes. Those tires aren't too pricey and get really good reviews, and some people are getting upwards of 60000 miles out of em'.

[Edahall]

Originally Posted by JPalmer81

Yeah, I agree about the 6.2/sm465 being a very easy to maintain driveline and that is what attracted me to it. I have had several trucks with the 350/sm465 combo and they were perfect in my eyes, although I have had a 6.0/NV4500 combo that was very nice too. I dont have the camper yet, but it will probably be around 5000lbs and def not more than 10000lbs and I only plan to use it to pull that a couple times a year. I am hoping the upgrades I will be doing to the motor will put it equal to a stock early cummins, so if i can get it to that point I think the 465 will do just fine with it. I appreciate your input, that is what this site is all about, learning from each other. Any other input you have is welcomed. Cant wait to get home and get going on this thing!

Keep in mind that the Cummins engine behaves much differently than a modded 6.2. Power comes right off idle and they tend to put out their max torque at 1400 rpm while a 6.2 is around 1900 rpm. On a 6.2, you have to rev it like a gas engine to be able to take advantage of the power.

The 1st generation Cummins were rated at 160 hp. With a pair of Stans headers and exhaust, you should be able to exceed that. However, the difference is that at 2000 rpms or less, the Cummins will flat out run away from the 6.2 since at those low rpm's, the 6.2 is not anywhere close to it's peak horsepower. Peak horsepower on a 6.2 comes at right around 3600 rpm's.

[JPalmer81]

Originally Posted by Edahall

Keep in mind that the Cummins engine behaves much differently than a modded 6.2. Power comes right off idle and they tend to put out their max torque at 1400 rpm while a 6.2 is around 1900 rpm. On a 6.2, you have to rev it like a gas engine to be able to take advantage of the power.

The 1st generation Cummins were rated at 160 hp. With a pair of Stans headers and exhaust, you should be able to exceed that. However, the difference is that at 2000 rpms or less, the Cummins will flat out run away from the 6.2 since at those low rpm's, the 6.2 is not anywhere close to it's peak horsepower. Peak horsepower on a 6.2 comes at right around 3600 rpm's.

And doing 60mph on the freeway with the sm465 should put me at about 3200 rpm's, or in that range so that will be in the 6.2's sweet spot for optimal performance and economy.

Another question, with upgrading the intake and exhaust, will that lower the RPM sweet spot range, since I will be achieving more complete combustion?

[Edahall]

Originally Posted by JPalmer81

And doing 60mph on the freeway with the sm465 should put me at about 3200 rpm's, or in that range so that will be in the 6.2's sweet spot for optimal performance and economy.

Another question, with upgrading the intake and exhaust, will that lower the RPM sweet spot range, since I will be achieving more complete combustion?

3200 rpm's will be the sweet spot for performance on the 6.2 but definitely not for solo fuel economy. For optimal fuel economy while empty, you want to be around 1800 rpm or less. After you get all the upgrades done on your truck and you pick out a trailer, it's highly possible you won't need those high RPM's to tow the trailer and you can swap in some axles that will tame those RPM's down a bit. I'm thinking more like 3.42's. My 6.2 Suburban pulled my 26 ft Airstream fine with 3.08 axles. The trailer weighed I'm guessing around 5500 lbs. At 60 mph, rpm's were around 1900 rpm's in direct drive. The engine did not have enough oomph to tow in overdrive at 1400 rpms.

Upgrading the intake and exhaust gave my 6.2 more power throughout it's rpm range. My guess is that max torque (1800 rpms) is about the same rpm as before the upgrades. Having driven a turbo 6.2 and 6.2 with headers, I will say that the 6.2 with headers seems to have more grunt at lower rpms than the turbo 6.2. The turbo 6.2 seems to have slightly more top end power though when the turbo spools up.

[JPalmer81]

Yeah, with my 4.10 gears the ole 6.2 is screaming at 60mph, thinking some 33" tires will help a little, might consider going down to 3.73's in the future. I don't think I will go any taller than that though.

[Edahall]

Originally Posted by JPalmer81

Yeah, with my 4.10 gears the ole 6.2 is screaming at 60mph, thinking some 33" tires will help a little, might consider going down to 3.73's in the future. I don't think I will go any taller than that though.

With 4.10's, your're running almost the same RPM's as my Suburban in 2nd gear with 3.08's!

You might want to consider an external overdrive unit of some sort. At the price of diesel these days, it would not take long for it to pay itself off.

[Mattman2010]

Originally Posted by JPalmer81

Yeah, with my 4.10 gears the ole 6.2 is screaming at 60mph, thinking some 33" tires will help a little, might consider going down to 3.73's in the future. I don't think I will go any taller than that though.

With 4.10 gears and 33's the 6.2 will be screaming. Most of the people I know that have a 6.2 and get good mpg are running 3.08 gears. While the power is at the higher end of the RPM the mpg are at the lower end of the RPM. I think the step down to 3.73's would be good with the fact that you wont be pulling the trailer all the time.

[JPalmer81]

Originally Posted by Edahall

With 4.10's, your're running almost the same RPM's as my Suburban in 2nd gear with 3.08's!

You might want to consider an external overdrive unit of some sort. At the price of diesel these days, it would not take long for it to pay itself off.

I have already been looking into it and I think if I do it it will be the ranger gear splitter. I know it has another stick coming through the floor, but most all the time I will just be using it for the overdrive, but if i am towing heavy I can split all the gears. Another thing other than the price that I like over the gear vendors is the fact that it hooks to the front of your tranny and not on the backside of the t-case so I can use it in 4x4, which will come in handy in Alaska.